--- loncom/xml/scripttag.pm	2000/07/06 21:07:26	1.1
+++ loncom/xml/scripttag.pm	2011/12/19 18:18:32	1.162
@@ -1,33 +1,668 @@
 # The LearningOnline Network with CAPA
 # <script> definiton
+#
+# $Id: scripttag.pm,v 1.162 2011/12/19 18:18:32 www Exp $
+#
+# Copyright Michigan State University Board of Trustees
+#
+# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
+#
+# LON-CAPA is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# LON-CAPA is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with LON-CAPA; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# /home/httpd/html/adm/gpl.txt
+#
+# http://www.lon-capa.org/
+#
 
-
-package Apache::scripttag; 
+package Apache::scripttag;
 
 use strict;
+use Apache::lonnet;
+use Apache::lonlocal;
+use Apache::style();
+
+#Globals
+# this used to pass around the standard callsub arguments to a tag func
+# so xmlparse can reenter the inner_xmlparse loop.
+
+@Apache::scripttag::parser_env = ();
+BEGIN {
+  &Apache::lonxml::register('Apache::scripttag',
+			    ('script','scriptlib','parserlib','import',
+			     'window','togglebox','display','storetc','physnet',
+			     'standalone','comment','num','parse','algebra',
+			     'LONCAPA_INTERNAL_TURN_STYLE_ON',
+			     'LONCAPA_INTERNAL_TURN_STYLE_OFF'));
+}
+
+sub start_LONCAPA_INTERNAL_TURN_STYLE_ON {
+    $Apache::lonxml::usestyle=1;
+    $Apache::lonxml::style_values='';
+    return ('','no');
+}
 
-sub BEGIN {
-  &Apache::lonxml::register('Apache::scripttag',('script'));
+sub end_LONCAPA_INTERNAL_TURN_STYLE_ON {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    my $end=&Apache::lonxml::get_param('end',$parstack,$safeeval);
+    if (defined($end)) {
+	&Apache::lonxml::end_tag($tagstack,$parstack,$token);
+    }
+    return ('','no');
+}
+
+sub start_LONCAPA_INTERNAL_TURN_STYLE_OFF {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+    $Apache::lonxml::usestyle=0;
+    my $end=&Apache::lonxml::get_param('end',$parstack,$safeeval);
+    if (!$end) {
+	$Apache::lonxml::style_values=$$parstack[-1];
+	$Apache::lonxml::style_end_values=$$parstack[-1];
+    } else {
+	$Apache::lonxml::style_values=$Apache::lonxml::style_end_values;
+	$Apache::lonxml::style_end_values='';
+    }
+    return ('','no');
+}
+
+sub end_LONCAPA_INTERNAL_TURN_STYLE_OFF {
+    return ('','no');
 }
 
 sub start_script {
-  my ($target,$token,@parstack)=@_;
-  
-#static mapping of params into variables
-#  map {$partstring =~ s/\$$_/$token->[2]->{$_}/g; } @{$token->[3]};
-  #	       print "want to use run\n";
-  my $decl='';
-  map {$decl .="my \$".$_.'='.$token->[2]->{$_}} @{$token->[3]};
-  print "declares $decl\n";
-  print "2:\n$token->[2]\n";
-  print "3:\n$token->[3]\n";
-#  &Apache::run::run($partstring,$safeeval);
-  
-#  $partstring = '';
+  my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+  @Apache::scripttag::parser_env = @_;
+  my $result='';
+  my $type= &Apache::lonxml::get_param('type',$parstack,$safeeval);
+  &Apache::lonxml::debug("found type of $type");
+  if ($type eq "loncapa/perl") {
+    if ( $target eq "modified" ) {
+	$result=$token->[4].&Apache::edit::modifiedfield('/script',$parser);
+    } elsif ( $target eq 'web' || $target eq 'tex' ||
+	      $target eq 'grade' || $target eq 'webgrade' ||
+	      $target eq 'answer' || $target eq 'analyze' ) {
+	my $bodytext=&Apache::lonxml::get_all_text_unbalanced("/script",$parser);
+	if (!$Apache::lonxml::default_homework_loaded) {
+	    &Apache::lonxml::default_homework_load($safeeval);
+	}
+	&Apache::run::run($bodytext,$safeeval);
+	if (($target eq 'answer') &&
+	    ($env{'form.answer_output_mode'} ne 'tex') &&
+	    ($Apache::lonhomework::viewgrades == 'F')) {
+	    $Apache::lonxml::evaluate--;
+	    my (undef,undef,$udom,$uname)=&Apache::lonnet::whichuser();
+	    $uname =~s/\W//g;
+	    $udom  =~s/\W//g;
+	    my $function_name = 
+		join('_','LONCAPA_scriptvars',$uname,$udom,
+		     $env{'form.counter'},$Apache::lonxml::curdepth);
+            &Apache::lonxml::add_script_result(
+	             &Apache::loncommon::modal_adhoc_window($function_name,500,500,
+                            '<pre>'.&Apache::run::dump($target,$safeeval).'</pre>',
+                            &mt('Script Vars'))."<br />");
+	}
+    } elsif ($target eq "edit" ) {
+      #&Apache::run::run($bodytext,$safeeval);
+      #$result="<br /> &lt;$token->[1]&gt; output: <br />$bodytext<br />Source:<br />";
+	my $bodytext=&Apache::lonxml::get_all_text_unbalanced("/script",$parser);
+	$result=&Apache::edit::tag_start($target,$token,'Script');
+	$result.=&Apache::edit::editfield($token->[1],$bodytext,'',80,4);
+    } elsif ($target eq 'meta') {
+	my $bodytext=&Apache::lonxml::get_all_text_unbalanced("/script",$parser);
+    }
+  } else {
+      my $bodytext=&Apache::lonxml::get_all_text_unbalanced("/script",$parser);
+      if ($target ne "meta" && $target ne 'tex' && $target ne 'answer') {
+	  $result = $token->[4];
+	  $result.=$bodytext;
+      }
+  }
+  return $result;
 }
 
 sub end_script {
-  
+  my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+  if ( $target eq "meta" ) { return ''; } 
+  my $type = &Apache::lonxml::get_param('type',$parstack,$safeeval);
+  my $result='';
+  #other script blocks need to survive
+  if ($type ne "loncapa/perl" && $target ne 'tex') {
+    return $token->[2];
+  } elsif ($target eq 'edit' ) {
+    return &Apache::edit::end_table();
+  } elsif ($target eq 'answer') {
+    $Apache::lonxml::evaluate++;
+  }
+  return '';
+}
+
+sub start_display {
+  my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+  @Apache::scripttag::parser_env = @_;
+  my $result;
+
+  if ( $target eq "modified" ) {
+      $result=$token->[4].&Apache::edit::modifiedfield("/display",$parser);
+  } elsif ( $target eq 'web' || $target eq 'tex' ||
+	    $target eq 'grade' || $target eq 'webgrade' ||
+	    $target eq 'answer' || $target eq 'analyze') {
+      my $bodytext=&Apache::lonxml::get_all_text_unbalanced("/display",$parser);
+      if (!$Apache::lonxml::default_homework_loaded) {
+	  &Apache::lonxml::default_homework_load($safeeval);
+      }
+      $result=&Apache::run::run($bodytext,$safeeval);
+      if ($target eq 'grade' || $target eq 'answer' ||
+	  $target eq 'analyze') {
+	  # grade/answer/analyxe should produce no output but if we
+	  # are redirecting, the redirecter should know what to do
+	  # with the output
+	  if (!$Apache::lonxml::redirection) { $result=''; }
+      }
+      $Apache::lonxml::post_evaluate=0;
+  } elsif ($target eq "edit" ) {
+    my $bodytext=&Apache::lonxml::get_all_text_unbalanced("/display",$parser);
+    #$result = 
+    #  "<br /> &lt;$token->[1]&gt; output: <br />$bodytext<br />Source:<br />";
+    #$result.=&Apache::edit::editfield($token->[1],$bodytext,'',40,1);
+    $result=&Apache::edit::tag_start($target,$token,'Script With Display');
+    $result.=&Apache::edit::editfield($token->[1],$bodytext,'',80,1)
+  } elsif ($target eq 'meta') {
+      my $bodytext=&Apache::lonxml::get_all_text_unbalanced("/display",$parser);
+  }
+  return $result;
+}
+
+sub end_display {
+  my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+  if ($target eq 'edit' ) { return &Apache::edit::end_table(); }
+  return '';
+}
+
+sub start_scriptlib {
+  my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+  my $bodytext;
+  my $result ='';
+  my $error='';
+
+  if ($target eq 'web' || $target eq 'tex' || $target eq 'grade' ||
+      $target eq 'meta' || $target eq 'edit' || $target eq 'answer' ||
+      $target eq 'analyze' || $target eq 'webgrade') {
+    $bodytext=$$parser[$#$parser]->get_text("/scriptlib");
+    $bodytext=&Apache::run::evaluate($bodytext,$safeeval,
+				     $$parstack[$#$parstack]);
+    my $location=&Apache::lonnet::filelocation($Apache::lonxml::pwd['-1'],
+					       $bodytext);
+    my $script=&Apache::lonnet::getfile($location);
+    if ($script == -1) {
+      if ($target eq 'edit') {
+        $error='</tr><tr><td>'.&mt('Errors').'</td><td colspan="2"><b>'.&mt(' Unable to find [_1]','<span class="LC_filename">'.$location.'</span>').'</b></td>'."\n";
+      } else {
+	&Apache::lonxml::error("<b> Unable to find <i>$location</i> for scriptlib</b>");
+	return "";
+      }
+    }
+    &Apache::run::run($script,$safeeval);
+    #&Apache::lonxml::debug("ran $bodytext:<br />".&Apache::lonnet::getfile($bodytext)."<br />");
+  }
+  if ($target eq "edit" ) {
+    $result=
+      &Apache::edit::tag_start($target,$token,'New Script Functions').
+	&Apache::edit::editline($token->[1],$bodytext,'scriptlib',40).
+            &Apache::edit::browse(undef,'textnode').
+	  $error.'</td></tr>'.
+	    &Apache::edit::end_table();
+  }
+  if ($target eq "modified" ) {
+      $result=$token->[4].&Apache::edit::modifiedfield("/scriptlib",$parser);
+  }
+  return $result;
+}
+
+sub end_scriptlib {
+  my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+  my @result;
+  if ($target eq "edit" ) { $result[1]='no'; }
+  return @result;
+}
+
+sub start_parserlib {
+  my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+  my $bodytext;
+  my $result ="";
+  my $error='';
+  if ($target eq 'web' || $target eq 'tex' || $target eq 'grade' ||
+      $target eq 'meta' || $target eq 'edit' || $target eq 'answer' ||
+      $target eq 'analyze' || $target eq 'webgrade') {
+    $bodytext=$$parser[$#$parser]->get_text("/parserlib");
+    $bodytext=&Apache::run::evaluate($bodytext,$safeeval,
+				     $$parstack[$#$parstack]);
+    my $location=&Apache::lonnet::filelocation($Apache::lonxml::pwd['-1'],
+					       $bodytext);
+    my $styletext=&Apache::lonnet::getfile($location);
+    #&Apache::lonxml::debug("found :$bodytext: in :$location: with :$styletext:");
+    if ($styletext == -1) {
+      if ($target eq 'edit') {
+	$error='</tr><tr><td>Errors</td><td colspan="2"><b> Unable to find <i>'.$location.'</i></b></td>'."\n";
+      } else {
+	&Apache::lonxml::error("<b> Unable to find <i>$location</i> for parserlib</b>");
+	return "";
+      }
+    }
+    %$style = ( %$style , &Apache::style::styleparser($target,$styletext));
+  }
+  if ($target eq "edit" ) {
+    $result=
+      &Apache::edit::tag_start($target,$token,'New Tag Definitions').
+	&Apache::edit::editline($token->[1],$bodytext,'',40).
+	  $error.'</td></tr>'.
+	    &Apache::edit::end_table();
+  }
+  if ($target eq "modified" ) {
+      $result=$token->[4].&Apache::edit::modifiedfield("/parserlib",$parser);
+  }
+  return $result;
+}
+
+sub end_parserlib {
+  my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+  my @result;
+  if ($target eq "edit" ) { $result[1]='no'; }
+  return @result;
+}
+
+sub start_window {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+    my $result = '';
+    if ($target eq 'web' || $target eq 'webgrade') {
+	&Apache::lonxml::startredirection;
+    } elsif ($target eq 'tex') {
+	$result = '\unskip\footnote{';
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_start($target,$token);
+	$result.=&Apache::edit::text_arg('Text of Link:','linktext',$token,70);
+	$result.=&Apache::edit::text_arg('Height:','height',$token,5);
+	$result.=&Apache::edit::text_arg('Width:','width',$token,5);
+	$result .=&Apache::edit::end_row().&Apache::edit::start_spanning_row();
+    } elsif ($target eq 'modified') {
+	my $constructtag=&Apache::edit::get_new_args($token,$parstack,
+						     $safeeval,'linktext',
+						     'width','height');
+	if ($constructtag) { $result=&Apache::edit::rebuild_tag($token); }
+    }
+    return $result;  
+}
+
+sub end_window {
+  my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+  my $result;
+  if ($target eq 'web' || $target eq 'webgrade') {
+    my $output=&Apache::lonxml::endredirection;
+    my $linktext= &Apache::lonxml::get_param('linktext',$parstack,$safeeval);
+    if (!$linktext) { $linktext='<sup>*</sup>'; }
+    my $width= &Apache::lonxml::get_param('width',$parstack,$safeeval);
+    if (!$width) { $width='500'; }
+    my $height= &Apache::lonxml::get_param('height',$parstack,$safeeval);
+    if (!$height) { $height='200'; }
+
+    my ($start_page,$end_page);
+    $result=&Apache::loncommon::modal_adhoc_window
+           ("LONCAPA_newwindow_$Apache::lonxml::curdepth",$width,$height,$output,$linktext);
+  } elsif ($target eq 'tex') {
+      $result = '}';
+  } else {
+      $result = '';
+  }
+  return $result; 
+}
+
+
+sub start_togglebox {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+    my $result = '';
+    if ($target eq 'web' || $target eq 'webgrade') {
+        my $id="LONCAPA_togglebox_$Apache::lonxml::curdepth";
+        my $heading=&Apache::lonxml::get_param('heading',$parstack,$safeeval);
+        unless ($heading) { $heading=''; } else { $heading.=' '; }
+        my $showtext=&Apache::lonxml::get_param('showtext',$parstack,$safeeval);
+        my $hidetext=&Apache::lonxml::get_param('hidetext',$parstack,$safeeval);
+        my $headerbg=&Apache::lonxml::get_param('headerbg',$parstack,$safeeval);
+        $result=&Apache::loncommon::start_togglebox($id,$heading,$headerbg,$hidetext,$showtext);
+    } elsif ($target eq 'tex') {
+        my $heading=&Apache::lonxml::get_param('heading',$parstack,$safeeval);
+        unless ($heading) { $heading=''; } else { $heading.=' '; }
+        $result = "\n\n".'\fbox{{\bf '.$heading.'} \qquad '."\n";
+    } elsif ($target eq 'edit') {
+        $result.=&Apache::edit::tag_start($target,$token);
+        $result.=&Apache::edit::text_arg('Heading:','heading',$token,70);
+        $result.=&Apache::edit::text_arg('Header Background:','headerbg',$token,7);
+        $result.=&Apache::edit::text_arg('Show text:','showtext',$token,10);
+        $result.=&Apache::edit::text_arg('Hide text:','hidetext',$token,10);
+        $result .=&Apache::edit::end_row().&Apache::edit::start_spanning_row();
+    } elsif ($target eq 'modified') {
+        my $constructtag=&Apache::edit::get_new_args($token,$parstack,
+                                                     $safeeval,'heading',
+                                                     'showtext','hidetext',
+                                                     'headerbg','textbg');
+        if ($constructtag) { $result=&Apache::edit::rebuild_tag($token); }
+    }
+    return $result;
+}
+
+sub end_togglebox {
+  my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+  my $result;
+  if ($target eq 'web' || $target eq 'webgrade') {
+    $result=&Apache::loncommon::end_togglebox();
+  } elsif ($target eq 'tex') {
+      $result = "}\n\n";
+  } else {
+      $result = '';
+  }
+  return $result;
+}
+
+
+
+sub start_import {
+  my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+  my $bodytext=$$parser[$#$parser]->get_text("/import");
+  my $result ="";
+
+  $bodytext=&Apache::run::evaluate($bodytext,$safeeval,$$parstack[$#$parstack]);
+
+  if ($target eq 'web' ||  $target eq 'webgrade' || $target eq 'grade' 
+      || $target eq 'answer' || $target eq 'tex' || $target eq 'analyze' ) {
+    # FIXME this probably needs to be smart about construction vs.
+    # non construction space.
+    my $location=&Apache::lonnet::filelocation($Apache::lonxml::pwd['-1'],$bodytext);
+    my $file=&Apache::lonnet::getfile($location);
+    if ($file == -1) {
+      &Apache::lonxml::error("<b> Unable to find <i>$bodytext as $location</i> for import</b>");
+      return "";
+    }
+    my $importmode=&Apache::lonxml::get_param('importmode',$parstack,$safeeval);
+    if (($importmode eq 'problem') || ($importmode eq 'part')) {
+# We are using import to import published problems
+       if (($importmode eq 'problem') || ($file=~/<part[^<]*>/s)) {
+# We explicitly don't want this to be a separate part or the problem already has parts
+          $file=~s/^\s*<problem>/<library>/s;
+	  $file=~s/<\/problem>\s*$/<\/library>/s;
+       } else {
+# We want this to be a separate part, but it currently is not
+          $file=~s/^\s*<problem>/<library><part>/s;
+	  $file=~s/<\/problem>\s*$/<\/part><\/library>/s;
+       }
+    }
+    my $dir=$location;
+    $dir=~s:/[^/]*$::;
+    #  &Apache::lonxml::debug("directory $dir $location file $file \n<b>END</b>\n");
+    my $id= &Apache::lonxml::get_id($parstack,$safeeval);
+    if (!$id) { $id=$Apache::lonxml::curdepth; }
+    push(@Apache::inputtags::import,$id);
+    push(@Apache::inputtags::importlist,$id);
+
+    &Apache::lonxml::newparser($parser,\$file,$dir);
+
+  } elsif ($target eq "edit" ) {
+    $result.=&Apache::edit::tag_start($target,$token);
+    my $location=$token->[1];
+    $location=~s/^\s*//s;
+    $location=~s/\s*$//s;
+    $result.=&Apache::edit::editline($location,$bodytext,'',40);
+    $result.=&Apache::edit::browse(undef,'textnode');
+    $result.= '&nbsp;<label>'.&mt('Import as:').
+              '<select name="importmode_'.$Apache::lonxml::curdepth.'">';
+    my %options=&Apache::lonlocal::texthash(''        => 'as standard library',
+                                            'problem' => 'as problem',
+                                            'part'    => 'as problem part(s)');
+    foreach my $option (sort(keys(%options))) {
+       $result.='<option value="'.$option.'"';
+       if ($option eq &Apache::lonxml::get_param('importmode',$parstack,$safeeval)) {
+          $result.=' selected="selected"';
+       }
+       $result.='>'.$options{$option}.'</option>';
+    }
+    $result.='</select></label>';
+    #FIXME this need to convert $bodytext to be a contruction space reference
+    #my $location=&Apache::lonnet::filelocation($Apache::lonxml::pwd['-1'],$bodytext);
+    #$result.="Click<a href=\"$location\">here</a> to edit<br />"
+  } elsif ($target eq 'modified') {
+      &Apache::edit::get_new_args($token,$parstack,$safeeval,'importmode');
+      $result='<import id="'.$token->[2]{'id'}.'" importmode="'.$token->[2]{'importmode'}.'">';
+      $result.=&Apache::edit::modifiedfield("/import",$parser);
+  } elsif ($target eq 'meta') {
+    my $id= &Apache::lonxml::get_id($parstack,$safeeval);
+    $result.='<import part="'.$Apache::inputtags::part;
+    if ($id) {
+      $result.='" id="'.$id;
+    }
+    $result.='" importmode="'.$token->[2]{'importmode'}.'">';
+    $result.=$bodytext;
+    $result.='</import>';
+  }
+  return $result;
+}
+
+sub end_import {
+  my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+  pop(@Apache::inputtags::import);
+  my $result;
+  if ($target eq 'edit' ) { $result=&Apache::edit::end_row.
+				&Apache::edit::end_table(); }
+  return $result;
+}
+
+sub start_storetc {
+  my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+  my $result = '';
+  &Apache::lonxml::startredirection;
+  return $result; 
+}
+
+sub end_storetc {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+    my $result;
+    my $output=&Apache::lonxml::endredirection;
+    $output =~ s/\"/\&quot\;/g;
+    $result = '{\bf '.$output.'.}}\write\tcfile{\protect\tcpc{ '.$output.'.}{\the\value{relpage}}}';
+    return $result;
+}
+
+
+sub start_physnet {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+    my $bodytext = '/adm/includes/physnet.sty';
+    my $location=&Apache::lonnet::filelocation($Apache::lonxml::pwd['-1'],$bodytext);
+    my $cbistyletext=&Apache::lonnet::getfile($location);
+
+    %$style = (%$style,&Apache::style::styleparser($target,$cbistyletext));
+    $$parser['-1']->unget_token($token);
+#    if ( defined($$style{'physnet'}) ) {
+#        &Apache::lonxml::newparser($parser,\$$style{'physnet'});
+#    }
+    return "";
+}
+
+sub end_physnet {
+  return '';
+}
+
+sub start_standalone {
+  my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+  my $result='';
+  if ($target eq 'web' || $target eq 'webgrade') {
+    if ( $env{'request.course.id'} ) {
+      my $inside = &Apache::lonxml::get_all_text("/standalone",$parser,$style);
+    } else {
+      $result='<table bgcolor="#E1E1E1" border="2"><tr><td>';
+    }
+  }
+  return $result;
+}
+
+sub end_standalone {
+  my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+  my $result='';
+  if ($target eq 'web' || $target eq 'webgrade' ) {
+    if ( $env{'request.course.id'} ) {
+    } else {
+      $result='</td></tr></table>';
+    }
+  }
+  return $result;
+}
+
+sub start_comment {
+  my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+  my $result='';
+  if ($target eq 'edit') {
+    $result=&Apache::edit::tag_start($target,$token);
+    my $bodytext=&Apache::lonxml::get_all_text("/comment",$parser,$style);
+    $result.=&Apache::edit::editfield($token->[1],$bodytext,'',80,4)
+  } elsif ( $target eq 'modified') {
+    $result=$token->[4].&Apache::edit::modifiedfield("/comment",$parser);
+  } elsif ( $target eq 'web'    || $target eq 'tex'  || $target eq 'grade'   ||
+	    $target eq 'answer' || $target eq 'meta' || $target eq 'analyze' ||
+	    $target eq 'webgrade') {
+    #normally throw away comments
+    my $bodytext=&Apache::lonxml::get_all_text("/comment",$parser,$style);
+  }
+  return $result;
+}
+
+sub end_comment {
+  my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
+  if ($target eq 'edit' ) { return &Apache::edit::end_table(); }
+  return '';
+}
+
+
+sub xmlparse {
+  my ($string) = @_;
+  &Apache::lonxml::debug("xmlparse recursion starting with $string");
+  # Apache::run::evaluate does an 'eval' on the name of the subroutine
+  # if it detects something that looks like a subroutine, this ends up calling
+  # things without any arguments and since perl is nice enough to pass
+  # along the default arguments when you don't explicitly say no arguments
+  # if you call &xmlparse, it gets &xmlparse passed as it argument.
+  # Same thing soccurs with &chemparse.
+  if ($string eq '&xmlparse') { return '&xmlparse'; }
+  if ($string eq '&chemparse') { return '&chemparse'; }
+  my ($target,$token,$tagstack,$parstack,$oldparser,$safeeval,$style)=
+    @Apache::scripttag::parser_env;
+  my @parser;
+  &Apache::lonxml::newparser(\@parser,\$string);
+  &Apache::lonxml::startredirection();
+  my $result=&Apache::lonxml::inner_xmlparse($target,$tagstack,
+					     $parstack,\@parser,
+					     $safeeval,$style);
+  $result.=&Apache::lonxml::endredirection();
+  &Apache::lonxml::debug("target is $target xmlparse recursion ending with $result");
+  return $result;
 }
+
+sub start_num {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
+    my $result = '';
+    my $inside = &Apache::lonxml::get_all_text_unbalanced("/num",$parser);
+    if ($target eq 'tex' || $target eq 'web' || $target eq 'webgrade') {
+	$inside=&Apache::run::evaluate($inside,$safeeval,$$parstack[-1]);
+	if (!$Apache::lonxml::default_homework_loaded) {
+	    &Apache::lonxml::default_homework_load($safeeval);
+	}
+	@Apache::scripttag::parser_env = @_;
+	my $format=&Apache::lonxml::get_param('format',$parstack,$safeeval);
+	$result=&Apache::run::run("return &prettyprint(q\0$inside\0,q\0$format\0);",$safeeval);
+    }    
+    return $result;
+}
+
+sub end_num {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
+    my $result = '';
+    return $result;
+}
+
+sub start_parse {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
+    my $result = '';
+    if ( $target eq 'web'    || $target eq 'tex'    ||
+	 $target eq 'grade'  || $target eq 'answer' ||
+	 $target eq 'analyze'|| $target eq 'webgrade') {
+	my $inside = &Apache::lonxml::get_all_text_unbalanced("/parse",$parser);
+	$inside=&Apache::run::evaluate($inside,$safeeval,$$parstack[-1]);
+	if (!$Apache::lonxml::default_homework_loaded) {
+	    &Apache::lonxml::default_homework_load($safeeval);
+	}
+	@Apache::scripttag::parser_env = @_;
+	$result=&Apache::run::run("return &xmlparse(q\0$inside\0);",$safeeval);
+	if ($target eq 'grade' || $target eq 'answer' ||
+	    $target eq 'analyze') {
+	    # grade/answer/analyxe should produce no output but if we
+	    # are redirecting, the redirecter should know what to do
+	    # with the output
+	    if (!$Apache::lonxml::redirection) { $result=''; }
+	}
+    }
+    return $result;
+}
+
+sub end_parse {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
+    my $result = '';
+    return $result;
+}
+
+sub start_algebra {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
+    my $result = '';
+    if ( $target eq 'web'     || $target eq 'tex'    ||
+	 $target eq 'grade'   || $target eq 'answer' ||
+	 $target eq 'analyze' || $target eq 'webgrade') {
+	my $inside = &Apache::lonxml::get_all_text_unbalanced("/algebra",$parser);
+	$inside = &Apache::run::evaluate($inside,$safeeval,$$parstack[-1]);
+	if ($target eq 'web' || $target eq 'tex' || $target eq 'analyze') {
+	    my $style=&Apache::lonxml::get_param('style',$parstack,$safeeval);
+	    $result=&Apache::lontexconvert::algebra($inside,$target,$style,$parstack,$safeeval);
+	}
+	$Apache::lonxml::post_evaluate=0;
+    }
+    return $result;
+}
+
+sub end_algebra {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
+    my $result = '';
+    return $result;
+}
+
 1;
 __END__
+
+=pod
+
+=head1 NAME
+
+Apache::scripttag.pm
+
+=head1 SYNOPSIS
+
+implements <script>, <scriptlib>, <parserlib>,
+and <import>
+
+This is part of the LearningOnline Network with CAPA project
+described at http://www.lon-capa.org.
+
+=cut
+